This invention relates to funnels for filling containers, and in particular, to an air pressure removal adaptor.
Heretofore, the prior art funnels having means to remove air pressure from a container as it is being filled by a liquid are provided with passages to carry air up through the funnel. An example of one such funnel is found in U.S. Pat. No. 426,667--Grissim, where a funnel having a frusto-conical liquid holding container with a large open end for pouring liquid into the liquid holding container and a small open end for dispensing liquids. A frusto-conical spout is connected to the small open end of the holding container. The Grissim funnel has a double wall construction whereby as a liquid is dispensed from the funnel any air in the container is forced between the double wall and out the top of the funnel.
Another U.S. patent having a passage for removing air is U.S. Pat. No. 766,616--Hagenbach. The small dispensing end of the frusto-conical shaped liquid holding container is attached to a screw threaded bottom. A cap screws into the screw threaded bottom. The cap has a conical lower end, adapted to fit into the mouth of a bottle, and a center opening which surrounds a tube of suitable length to extend near the bottom of the bottle. Air escapes through the opening in the cap, and into an air-tube which extends a little below the upper edge of the funnel down through the bottom of the funnel and into a cavity formed between the screw threaded bottom and the cap.
U.S. Pat. No. 4,494,585--Waldecker, discloses a funnel having vent tube down through the funnel outlet end to the mouth of the outlet.
The vent means in U.S. Pat. No. 5,074,343--Tyree includes a plurality of vent holes in a funnel displacer section. Air escapes from a bottle through the vent holes and through the fluid filling the bottle.